SAN FRANCISCO — Two years after he sold the biotechnology company Genzyme Corp. to a French pharmaceutical giant, Henri A. Termeer isn’t exactly settling into the comforts of retirement at his seaside homes north of Boston and in Maine.

The 66-year-old Termeer, who left the Cambridge company in April 2011, certainly doesn’t need to keep working for financial reasons. He cashed in Genzyme shares worth at least $145.9 million and walked off with a $12.5 million severance package.

But Termeer, a life sciences legend, continues to keep a frenetic work pace, motivated by what he says is the desire to keep getting new treatments to patients.

He sits on the boards of more than a dozen biotechs — including Cambridge firms AVEO Pharmaceuticals Inc. and Verastem Inc. — and large nonprofit organizations ranging from Massachusetts General Hospital to the Massachusetts Institute of Technology.

Get Business Headlines in your inbox:

The Globe's latest business headlines delivered every morning, Monday through Friday.

He is also mentoring young entrepreneurs, and investing in their start-ups, on both sides of the Atlantic. Termeer was a fixture here at the recent J.P. Morgan Healthcare Conference — the life sciences industry’s premiere investment gathering — catching up with old friends in the business, holding court at marathon meetings, and taking time out to attend a reunion of Genzyme alums at a private Bay Area home.

After logging two 14-hour days before heading back to Boston, the avuncular Termeer deadpanned, “I could have filled the next two days, too. It’s an insatiable world.”

He admits to missing the experience of addressing a ­ crowd of investors from the ­podium and updating them on the progress of drugs being developed by Genzyme, a pioneer in treatments for rare genetic disorders. Some of those high-tech medicines proved lucrative for Genzyme; they cost up to $300,000 per patient annually.

“I did it for 25 years,” Termeer said of running the company. “You feel like you still need to get up there [in front of an audience]. But I’m very free here now. I can get a lot more done.”

Former colleagues marvel at Termeer’s indefatigable presence.

“Henri is a force of nature,” said Elias Zerhouni, president of global research and development at Sanofi SA, the Paris-based drug behemoth that paid $20.1 billion for Genzyme in 2011. “He didn’t want a formal role, but I still ask him for ­advice from time to time.”

Termeer is quick to offer advice that is impromptu and sometimes unsolicited. For instance, after AVEO chief executive Tuan Ha-Ngoc completed his presentation at this month’s health conference — confidently telling investors that his company “stands ready” to bring its kidney cancer drug to market — Termeer buttonholed Ha-Ngoc for a quick post-mortem.

“Your presentation was very good, very tight,” said Termeer, who chairs the AVEO board.

Earlier, the Dutch-born Termeer met with Daniel de Boer, the 29-year-old chief executive of ProQR Therapeutics BV, a start-up from Leiden in the Netherlands that has licensed a compound from Boston scientists to develop a treatment for cystic fibrosis.

De Boer, whose 3-year-old son suffers from the genetic disease, first approached Termeer in Boston last year through an introduction by a mutual ­acquaintance, Dutch biotechnology leader Dinko Valerio.

Last year, Termeer donated $10 million to Massachusetts General Hospital to establish a targeted therapies center.

“It took me a while to get into Henri’s office,” de Boer recalled. “I just had an idea to start a company in the cystic ­fibrosis space. I didn’t have anything else.”

Ultimately, Termeer agreed to invest an undisclosed sum in de Boer’s company, and to serve as an informal business adviser. “He is very valuable to me as a starting entrepreneur,” de Boer said. “I need a role model to learn the business from.”

He is far from the only entrepreneur, or institution, to benefit from Termeer’s generosity. Last year, Termeer donated $10 million to Mass­­achusetts General Hospital to establish a targeted therapies center. The goal is to advance the field of personalized medicine for cancer patients.

He has also been mentoring Dimitri Krainc, a Slovenia-born Mass. General neurologist who, with Termeer’s backing, has launched Lysosomal Therapeutics Inc. The fledgling Boston company is seeking to develop a treatment for Parkinson’s and other neurodegenerative diseases.

Krainc said he frequently leans on Termeer for advice in building the business.

”We’re in contact by e-mail, phone, or in person weekly,” Krainc said. “It’s fun to meet with Henri. He listens. He’s got incredibly good judgment. And he’s very focused on the ­patients.”

Indeed, for Termeer, who was an industry leader in reaching out to patient groups as part of the drug development process, there is the element of unfinished business in his work with both Krainc and de Boer. Genzyme, under Termeer, had underwritten research projects that never bore fruit in treatments for both cystic fibrosis and Parkinson’s disease.

“Henri did a lot of work on cystic fibrosis (at Genzyme),” de Boer said, “and he’s eager to solve that problem. He’s a very tough businessman. But in the end, what really moves him is getting products to patients.”

Termeer, who authorized hundreds of millions of dollars in investments in those failed drug research projects, doesn’t deny he would love to see his proteges succeed where he fell short.

“It’s something that’s on your mind,” he said. “If I can make a difference, I’ll do it.”

Correction: Because of a reporting error, an earlier version of this story gave an incorrect spelling for the name of the Boston start-up company being advised by former Genzyme Corp. chief executive Henri A. Termeer. It is Lysosomal Therapeutics Inc.

BostonGlobe.com complimentary digital access has been provided to you, without a subscription, for free starting today and ending in 14 days. After the free trial period, your free BostonGlobe.com digital access will stop immediately unless you sign up for BostonGlobe.com digital subscription. Current print and digital subscribers are not eligible for the free trial.

Thanks & Welcome to Globe.com

You now have unlimited access for the next two weeks.

BostonGlobe.com complimentary digital access has been provided to you, without a subscription, for free starting today and ending in 14 days. After the free trial period, your free BostonGlobe.com digital access will stop immediately unless you sign up for BostonGlobe.com digital subscription. Current print and digital subscribers are not eligible for the free trial.